Lens barrel

ABSTRACT

Provided is a lens barrel with which it is possible to suppress the influence of a disturbance magnetic field on a magnetic sensor. A coil that surrounds an outer periphery of a lens frame, magnetic force applying members that are disposed at a plurality of positions around the lens frame, and a magnetic sensor that detects an amount of movement of the lens frame are provided. In a plane orthogonal to an optical axis, the magnetic force applying members that are disposed on both sides adjacent to the magnetic sensor are disposed in postures in which a first angle (θ1, θ2) formed between a first straight line (L1) and a second straight line (L2) is smaller than 45°, the first straight line (L1) being a straight line passing through the magnetic sensor and the optical axis and the second straight line (L2) being a straight line orthogonal to surfaces of a first yoke and a second yoke of the magnetic force applying member that face each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of PCT InternationalApplication No. PCT/JP2021/027445 filed on Jul. 26, 2021 claimingpriority under 35 U.S.C § 119(a) to Japanese Patent Application No.2020-128982 filed on Jul. 30, 2020. Each of the above applications ishereby expressly incorporated by reference, in its entirety, into thepresent application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a lens barrel.

2. Description of the Related Art

A lens barrel in which a lens is driven by means of a voice coil motor(VCM) is known. In addition, a technique, in which the position of alens is detected by means of a magnetic sensor in a lens barrel in whichthe lens is driven by means of a voice coil motor, is known (forexample, JP2008-185749A, WO2017/187933A, and the like).

SUMMARY OF THE INVENTION

One embodiment according to the present disclosed technology provides alens barrel with which it is possible to suppress the influence of adisturbance magnetic field on a magnetic sensor.

(1) A lens barrel including a first shaft and a second shaft that aredisposed along an optical axis, a lens frame that includes a firstsliding portion sliding along the first shaft and a second slidingportion sliding along the second shaft and that is supported to bemovable along the optical axis, a coil that is mounted to the lens frameand that surrounds an outer periphery of the lens frame, magnetic forceapplying members that are disposed at a plurality of positions aroundthe lens frame and that apply magnetic forces to the coil, and amagnetic sensor that detects an amount of movement of the lens frame, inwhich the magnetic force applying member includes a flat plate-shapedfirst yoke and a flat plate-shaped second yoke that are disposed insideand outside the coil to face each other with the coil interposedtherebetween and a magnet that is provided at the first yoke and/or thesecond yoke, and, in a plane orthogonal to the optical axis, themagnetic force applying members that are disposed on both sides adjacentto the magnetic sensor are disposed in postures in which a first angleformed between a first straight line and a second straight line issmaller than 45°, the first straight line being a straight line passingthrough the magnetic sensor and the optical axis and the second straightline being a straight line orthogonal to surfaces of the first yoke andthe second yoke of the magnetic force applying member that face eachother.

(2) The lens barrel of (1), in which the first angle is equal to orsmaller than 35°.

(3) The lens barrel of (1) or (2), in which, in the plane orthogonal tothe optical axis, the magnetic force applying members that are disposedon both sides adjacent to the magnetic sensor are symmetrically disposedwith respect to the first straight line.

(4) The lens barrel of any one of (1) to (3), in which, in the planeorthogonal to the optical axis, the magnetic sensor is disposed at aposition at which the first straight line and a third straight linecross at a right angle, the third straight line being a straight linepassing through the first shaft and the optical axis.

(5) The lens barrel of (4), in which, in the plane orthogonal to theoptical axis, the plurality of magnetic force applying members aresymmetrically disposed with respect to the third straight line.

(6) The lens barrel of any one of (1) to (5), in which, in the planeorthogonal to the optical axis, the magnetic force applying members thatare disposed on both sides adjacent to the magnetic sensor are disposedat positions at which a second angle formed between the first straightline and a fourth straight line is equal to or larger than 35° andsmaller than 55°, the fourth straight line being a straight line passingthrough the magnetic force applying member and the optical axis.

(7) The lens barrel of (6), in which the first angle is smaller than thesecond angle.

(8) The lens barrel of any one of (1) to (7), in which, in the planeorthogonal to the optical axis, the first shaft and the second shaft aresymmetrically disposed with respect to the first straight line.

(9) The lens barrel of any one of (1) to (8), in which the magneticsensor is disposed within a disposition range of the magnet in adirection along the optical axis.

(10) The lens barrel of any one of (1) to (9), in which the firstsliding portion includes a hole into which the first shaft is inserted,and the second sliding portion includes a groove to which the secondshaft is fitted.

(11) The lens barrel of any one of (1) to (10), in which the firstsliding portion is disposed inside the coil, and the second slidingportion is disposed outside the coil.

(12) The lens barrel of any one of (1) to (11), in which the first yokeand/or the second yoke has a width and/or a thickness corresponding to amagnetic flux density generated by the magnetic force applying member.

(13) The lens barrel of any one of (1) to (12), in which the lens frameincludes a magnetic scale provided at an outer peripheral portion of thelens frame, and the magnetic sensor is disposed to face the magneticscale and reads magnetic information of the magnetic scale to detect theamount of movement of the lens frame.

(14) A lens barrel including a first shaft and a second shaft that aredisposed along an optical axis, a lens frame that includes a firstsliding portion sliding along the first shaft and a second slidingportion sliding along the second shaft and that is supported to bemovable along the optical axis, a coil that is mounted to the lens frameand that surrounds an outer periphery of the lens frame, magnetic forceapplying members that are disposed at a plurality of positions aroundthe lens frame and that apply magnetic forces to the coil, and amagnetic sensor that detects an amount of movement of the lens frame, inwhich the magnetic force applying member includes a flat plate-shapedmagnet that is disposed to face the coil, and a normal line from a flatsurface portion of the magnet from the optical axis and a straight linepassing through the optical axis and the flat surface portion of themagnet form an angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a schematic configuration of aninterchangeable lens.

FIG. 2 is a side sectional view showing a schematic configuration of afocus unit.

FIG. 3 is a side sectional view showing the schematic configuration ofthe focus unit.

FIG. 4 is a front sectional view showing the schematic configuration ofthe focus unit.

FIG. 5 is a perspective view showing a configuration of a second baseframe rear frame.

FIG. 6 is a perspective view showing the configuration of the secondbase frame rear frame.

FIG. 7 is a perspective view showing a configuration of a second movableframe.

FIG. 8 is a perspective view showing configurations of magnetic forceapplying units.

FIG. 9 is an explanatory view of the installation positions of fourmagnetic force applying units.

FIG. 10 is an explanatory view of the installation postures of themagnetic force applying units.

FIG. 11 is a graph showing a relationship between the installation angleof a magnetic force applying unit and a magnetic flux density.

FIG. 12 is a graph showing a relationship between a distance between acoil and an MR sensor and a magnetic field in a z-direction.

FIG. 13 is a graph showing a relationship between the installationposition of the MR sensor with respect to the magnetic force applyingunit in the z-direction and a magnetic flux density in the z-direction.

FIG. 14 is an explanatory view of the disposition range of magnets andthe installation position of the MR sensor.

FIG. 15 is a contour diagram of the magnetic flux density of themagnetic force applying units.

FIG. 16 is an enlarged view of a portion of FIG. 15 .

FIG. 17 is a perspective view showing an example of a yoke of which thewidth is adjusted in accordance with the distribution of the magneticflux density.

FIG. 18 is a perspective view showing a schematic configuration of anOIS unit.

FIG. 19 is a front view of the OIS unit shown in FIG. 18 .

FIG. 20 is an exploded perspective view of the OIS unit shown in FIG. 18.

FIG. 21 is a perspective view showing a configuration of a first baseframe.

FIG. 22 is a front view of the first base frame.

FIG. 23 is a perspective view showing a configuration of a first movableframe.

FIG. 24 is a front view of the first movable frame.

FIG. 25 is a perspective view showing a configuration of a swingingblock.

FIG. 26 is a perspective view showing schematic configurations of afirst voice coil motor and a second voice coil motor.

FIG. 27 is a front view of the first movable frame with coils attachedthereto.

FIG. 28 is an explanatory view of a relationship between disposition ofa first rigid ball holding portion and disposition of a third rigid ballholding portion.

FIG. 29 is a perspective view showing configurations of a first flexibleprinted circuit and a second flexible printed circuit.

FIG. 30 is a front view showing the configurations of the first flexibleprinted circuit and the second flexible printed circuit.

FIG. 31 is a perspective view of a modification example of a unitcomposed of a magnet and a yoke.

FIG. 32 is a graph about comparison between a Lorentz force generated ina case where the shapes of outer peripheral portions of magnets arelinear shapes and a Lorentz force generated in a case where the shapesof the outer peripheral portions of the magnets are arc shapes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a preferred embodiment of the present invention will bedescribed in detail with reference to the attached drawings.

[About Lens Barrel in which Voice Coil Motor is Used]

In a case where a voice coil motor is used to drive a lens, aconfiguration in which a coil is attached to surround an outer peripheryof a lens frame and magnets are disposed at a plurality of positionsaround the lens frame is effective in obtaining large thrust whilemaking the entire configuration compact. In this case, the larger thenumber of magnets installed is, the larger the thrust obtained is.

However, increasing the number of magnets installed causes a problemthat a sensor and a magnet are disposed to be near to each other and thesensor is influenced by the magnet in a case where the position of thelens is detected by means of a magnetic sensor. Specifically, there is aproblem that the output from the sensor is reduced because of theinfluence of a disturbance magnetic field.

In the following embodiment, a configuration for suppression of theinfluence of a disturbance magnetic field on a magnetic sensor in a lensbarrel in which a lens is driven by means of a voice coil motor will bedescribed.

[Overall Configuration of Lens Barrel]

Here, a case where the present invention is applied to aninterchangeable lens of an interchangeable lens camera will be describedas an example.

FIG. 1 is a cross-sectional view showing a schematic configuration of aninterchangeable lens of the present embodiment.

An interchangeable lens 1 shown in the drawing is an interchangeablelens for a digital still camera including a focus mechanism, a zoommechanism, and an optical image stabilizer (OIS). The interchangeablelens 1 is attachably and detachably mounted to a camera body (not shown)via a mount 2 provided at a proximal end portion.

As shown in FIG. 1 , a lens barrel 10 of the interchangeable lens 1 ofthe present embodiment includes a first fixed cylinder 12, a camcylinder 14, a moving cylinder 16, and a second fixed cylinder 18arranged in this order from a radially inner side.

Both of the first fixed cylinder 12 and the second fixed cylinder 18 arefixed to a mount base member 20 at the proximal end portion (an endportion on an image side). The mount 2 is attached to the mount basemember 20. A focus ring 3 for a focusing operation, a zoom ring 4 for azooming operation, a stop ring 5 for a stop operation, and the like areprovided on an outer periphery of the second fixed cylinder 18.

The cam cylinder 14 includes a cam groove (not shown). The cam cylinder14 is fitted to an outer periphery of the first fixed cylinder 12 and isheld to be rotatable around an optical axis Z. The cam cylinder 14 isconnected to the zoom ring 4 via a connecting member (not shown).Therefore, in a case where the zoom ring 4 is rotated, the cam cylinder14 is rotated.

The moving cylinder 16 is fitted to an outer periphery of the camcylinder 14 and is held to be movable along the optical axis Z. In acase where the cam cylinder 14 is rotated, the moving cylinder 16 ismoved forward and backward along the optical axis Z by a cam mechanism(not shown).

Inside the lens barrel 10, a first lens group G1, a second lens groupG2, a third lens group G3, a fourth lens group G4, a fifth lens groupG5, a sixth lens group G6, and a seventh lens group G7 are provided inthis order from an object side (the left side in FIG. 1 ) along theoptical axis Z. A stop is provided between the second lens group G2 andthe third lens group G3. Each lens group is composed of at least onelens. The first lens group G1 to the sixth lens group G6 are lens groupsthat move in the case of zooming. The seventh lens group G7 is a lensgroup fixed in the case of zooming.

The first lens group G1 is held by a first lens group holding frame 22.The first lens group holding frame 22 is held by being fixed to a distalend of the moving cylinder 16. Therefore, the first lens group holdingframe 22 is moved in the case of movement of the moving cylinder 16.

The second lens group G2 is a lens group that constitutes a camerashake-correction lens. The second lens group G2 is held by a firstmovable frame 202. The first movable frame 202 is held to be movable ina plane orthogonal to the optical axis Z with respect to a first baseframe 204. A holding structure and a driving structure for the firstmovable frame 202 will be described later. The first base frame 204 isheld to be movable along the optical axis Z at an inner peripheralportion of the first fixed cylinder 12. In a case where the cam cylinder14 is rotated, the first base frame 204 is moved forward and backwardalong the optical axis Z by a cam mechanism (not shown).

The third lens group G3 to the sixth lens group G6 are held by a secondbase frame 102. The second base frame 102 is held to be movable alongthe optical axis Z at the inner peripheral portion of the first fixedcylinder 12. In a case where the cam cylinder 14 is rotated, the secondbase frame 102 is moved forward and backward along the optical axis Z bya cam mechanism (not shown).

Here, the third lens group G3, the fourth lens group G4, and the sixthlens group G6 are held by being fixed to the second base frame 102.

Meanwhile, the fifth lens group G5 is held to be movable along theoptical axis Z in the second base frame 102. The fifth lens group G5 isa lens group that constitutes a focus lens. In the case of theinterchangeable lens 1, focus adjustment is performed by moving thefifth lens group G5 forward and backward along the optical axis Z. Thefifth lens group G5 is held by a second movable frame 104 and supportedto be movable along the optical axis Z in the second base frame 102. Inaddition, the second movable frame 104 is moved by being driven by anactuator provided at the second base frame 102. A holding structure anda driving structure for the second movable frame 104 will be describedlater.

The seventh lens group G7 is held by a seventh lens group holding frame24. The seventh lens group holding frame 24 is held by being fixed to aproximal end portion of the first fixed cylinder 12.

Regarding a stop, a stop unit 30 including the drive mechanism thereforis integrally attached to a distal end portion of the second base frame102 and is disposed at a predetermined position.

[Focus Unit]

[Holding Structure for Fifth Lens Group]

A unit based on the second base frame 102 constitutes a focus unit 100of the interchangeable lens 1.

FIGS. 2 and 3 are side sectional views showing a schematic configurationof the focus unit. FIG. 4 is a front sectional view showing a schematicconfiguration of the focus unit. FIG. 2 corresponds to a cross sectiontaken along line 2-2 of FIG. 4 . FIG. 3 corresponds to a cross sectiontaken along line 3-3 of FIG. 4 . FIG. 4 corresponds to a cross sectiontaken along line 4-4 of FIGS. 2 and 3 .

As shown in FIGS. 2 and 3 , the second base frame 102 is composed of asecond base frame front frame 102F and a second base frame rear frame102R and is configured to be dividable in a front-rear direction. Thesecond base frame front frame 102F and the second base frame rear frame102R are connected and integrated with each other by means of a screw(not shown). The second base frame front frame 102F and the second baseframe rear frame 102R integrated with each other are disposed coaxially.

The second base frame front frame 102F includes a third lens groupholding portion 106 and a fourth lens group holding portion 108. Thethird lens group G3 is held by the third lens group holding portion 106.The fourth lens group G4 is held by the fourth lens group holdingportion 108.

In addition, the second base frame front frame 102F includes cam pins(not shown) at three positions on an outer peripheral portion. The campins are fitted to a linear movement groove (not shown) that the firstfixed cylinder 12 includes and a cam groove (not shown) that the camcylinder 14 includes. Accordingly, in a case where the cam cylinder 14is rotated, the second base frame 102 moves forward and backward alongthe optical axis Z.

In addition, the second base frame rear frame 102R includes a sixth lensgroup holding portion 110. The sixth lens group G6 is held by the sixthlens group holding portion 110.

As described above, the fifth lens group G5 is held by the secondmovable frame 104 and supported to be movable along the optical axis Zin the second base frame 102.

As shown in FIGS. 2 to 4 , a main shaft 112 and a sub shaft 114 thatguide the movement of the second movable frame 104 are provided in thesecond base frame 102. The main shaft 112 is an example of a firstshaft. The sub shaft 114 is an example of a second shaft. The main shaft112 and the sub shaft 114 are disposed along the optical axis Z.Further, the main shaft 112 and the sub shaft 114 are disposed on astraight line passing through the optical axis Z in a plane orthogonalto the optical axis Z.

FIG. 5 and FIG. 6 are perspective views showing the configuration of thesecond base frame rear frame. In addition, FIG. 7 is a perspective viewshowing the configuration of the second movable frame.

The second movable frame 104 moves along the optical axis Z by slidingalong the main shaft 112 and the sub shaft 114. The second movable frame104 is an example of a lens frame. The second movable frame 104 includesa main sliding portion 116 that slides along the main shaft 112 and asub sliding portion 118 that slides along the sub shaft 114. The mainsliding portion 116 is an example of a first sliding portion. The subsliding portion 118 is an example of a second sliding portion.

The main sliding portion 116 has a plate-like shape extending along theoptical axis Z, and includes holes 116A into which the main shaft 112 isinserted at both ends in a direction along the optical axis Z. The mainsliding portion 116 slides along the main shaft 112 with the main shaft112 inserted into the holes 116A at both ends of the main slidingportion 116.

The sub sliding portion 118 includes a groove 118A to which the subshaft 114 is fitted. The sub sliding portion 118 slides along the subshaft 114 with the sub shaft 114 fitted to the groove 118A.

Regarding the second movable frame 104, stable guidance in an opticalaxis direction is realized mainly by the main sliding portion 116. Forrealization of the stable guidance, the main sliding portion 116 isconfigured to have a sufficient length along the optical axis Z. The subsliding portion 118 mainly prevents the second movable frame 104 frommoving or rotating (rotating about the main shaft) in a plane orthogonalto the optical axis Z.

[Driving Structure for Second Movable Frame]

In the case of the focus unit 100 according to the present embodiment, avoice coil motor 120 is used as an actuator for the purpose of drivingthe second movable frame 104.

The voice coil motor 120 according to the present embodiment is composedof a coil 122 and four magnetic force applying units 124A to 124D. Thecoil 122 is attached to the second movable frame 104. The four magneticforce applying units 124A to 124D are attached to the second base frame102. That is, the voice coil motor 120 according to the presentembodiment is composed of a moving coil type voice coil motor of which acoil side is movable.

Hereinafter, as necessary, the four magnetic force applying units 124Ato 124D will be distinguished from each other with the magnetic forceapplying unit 124A being referred to as a first magnetic force applyingunit, the magnetic force applying unit 124B being referred to as asecond magnetic force applying unit, the magnetic force applying unit124C being referred to as a third magnetic force applying unit, and themagnetic force applying unit 124D being referred to as a fourth magneticforce applying unit. The magnetic force applying units 124A to 124D areexamples of magnetic force applying members.

As shown in FIGS. 4 and 7 , the coil 122 is configured as a so-calledall-around coil, is wound around the second movable frame 104, and isattached to surround the periphery of the second movable frame 104.Particularly, in the case of the focus unit 100 of the presentembodiment, the coil 122 is wound along a path that passes through aposition outward of the main shaft 112 and a position inward of the subshaft 114 and the coil 122 is attached to the periphery of the secondmovable frame 104. Accordingly, the following effects are achieved.

One of the effects is that the strength of the second movable frame 104can be improved. Since the coil 122 is disposed along the path thatpasses through the position outward (radially outward) of the main shaft112, a space (a so-called notch) for passage of the coil 122 does notneed to be provided between a lens holding portion (a holding portion ofthe fifth lens group G5) of the second movable frame 104 and the mainsliding portion 116. Accordingly, it possible to provide a connectingportion, a reinforcing rib, or the like with respect to the main slidingportion 116 without an increase in size of the second movable frame 104.As a result, the strength of the second movable frame 104 is improved,and unnecessary resonance frequency in the case of driving the voicecoil motor 120 can be made high.

The other one of the effects is that power consumption can be reduced.Since the coil 122 is disposed along the path that passes through theposition inward of the sub shaft 114, the coil length can be set to theminimum necessary length. The sub sliding portion 118 is not required tohave the same strength as the main sliding portion 116 because of thenature thereof. Therefore, a space (a so-called notch) for passage ofthe coil can be disposed between the sub sliding portion 118 and thelens holding portion. Accordingly, the path for the coil can beshortened and the coil length can be shortened. In addition,accordingly, resistance can be reduced and power consumption can bereduced.

Each of the magnetic force applying units 124A to 124D is configured asa unit in which a magnet 126 and a yoke 128 are integrated with eachother. The configurations of the magnetic force applying units 124A to124D are the same as each other.

FIG. 8 is a perspective view showing the configurations of the magneticforce applying units.

The yoke 128 is made of a magnetic material (for example, iron). Theyoke 128 has a U-like shape and includes an inner yoke portion 128I thatis disposed on an inner peripheral side in the case of attachment to thesecond base frame 102 and an outer yoke portion 128O that is disposed onan outer peripheral side. Each of the inner yoke portion 128I and theouter yoke portion 128O has a rectangular flat plate-like shapeextending along the optical axis Z and the inner yoke portion 128I andthe outer yoke portion 128O are disposed to face each other with apredetermined gap provided therebetween. The inner yoke portion 128I isan example of a first yoke. The outer yoke portion 128O is an example ofa second yoke.

The magnet 126 has a rectangular flat plate-like shape extending alongthe optical axis Z and is integrally attached to an inner surface of theouter yoke portion 128O. By being attached to the outer yoke portion128O, the magnet 126 is disposed such that the magnet 126 and the inneryoke portion 128I face each other with a predetermined gap providedtherebetween.

As described above, the four magnetic force applying units 124A to 124Dare attached to the second base frame 102. As shown in FIG. 4 , on theinner peripheral portion of the second base frame 102, magnetic forceapplying unit holding portions 130A to 130D are provided at fourpositions in a circumferential direction. The magnetic force applyingunit holding portions 130A to 130D are composed of recess portions towhich the magnetic force applying units 124A to 124D are fitted. Bybeing attached to the magnetic force applying unit holding portions 130Ato 130D, the magnetic force applying units 124A to 124D are attached atpredetermined positions in the second base frame 102 in predeterminedpostures. Accordingly, the magnetic force applying units 124A to 124Dare attached at predetermined positions around the second movable frame104 in the predetermined postures.

The positions at which the magnetic force applying units 124A to 124Dare installed and the postures in which the magnetic force applyingunits 124A to 124D are installed are determined based on a relationshipbetween the installation position of the main shaft 112 and theinstallation position of a magnetic sensor. This point will be describedlater.

As shown in FIG. 4 , the coil 122 provided for the second movable frame104 is disposed to pass through gaps between the inner yoke portions128I and the magnets 126 of the magnetic force applying units 124A to124D. The coil 122 passing through the gaps is disposed to be parallelto inner surfaces (surfaces facing the coil 122) of the magnets 126 thatare configured in a flat plate-like shape. In other words, the magnets126 are disposed to face the coil 122 and flat surface portions thereofthat face the coil 122 are disposed to be parallel to the coil 122.

According to the above-described configuration, the second movable frame104 moves along the optical axis Z in a case where a voltage is appliedto the coil 122.

[Position Detection Mechanism of Fifth Lens Group]

The position of the second movable frame 104 with respect to the secondbase frame 102 is detected by a fifth lens group position detectionmechanism. More specifically, the position with respect to the secondbase frame 102 is a position relative to a reference position (an originposition) set for the second base frame 102. The fifth lens groupposition detection mechanism includes a reference position detector thatdetects that the fifth lens group G5 is positioned at a referenceposition and a movement amount detector that detects the amount ofmovement (the amount of displacement) of the fifth lens group G5. Thefifth lens group position detection mechanism detects that the fifthlens group G5 is positioned at the reference position by means of thereference position detector and detects the amount of movement from thereference position by means of the movement amount detector to detectthe position of the fifth lens group G5 with respect to the second baseframe 102.

The reference position detector is composed of a light screen 132 and aphoto interrupter 134. The light screen 132 is provided at the secondmovable frame 104. The photo interrupter 134 is provided at the secondbase frame 102. The reference position detector detects that the fifthlens group G5 is positioned at the reference position by detecting thelight screen 132 with the photo interrupter 134. Therefore, theinstallation positions of the light screen 132 and the photo interrupter134 are adjusted such that the light screen 132 is detected at a timewhen the fifth lens group G5 is positioned at the reference position.

The movement amount detector is composed of a magnetic scale 136 and amagneto resistive sensor (MR sensor) 138 that detects magneticinformation (the N pole and the S pole) of the magnetic scale 136. TheMR sensor 138 is an example of a magnetic sensor.

The magnetic scale 136 has a bar-like shape, and has a structure (amagnetization sheet) in which N poles and S poles are magnetized at aconstant pitch along a longitudinal direction. The magnetic scale 136 isprovided on an outer peripheral portion of the second movable frame 104.The installation position of the magnetic scale 136 will be describedlater. The magnetic scale 136 is disposed along the direction ofmovement (a direction along the optical axis Z) of the second movableframe 104.

The MR sensor 138 is provided at the second base frame 102. The MRsensor 138 is disposed on a movement path of the magnetic scale 136. TheMR sensor 138 is disposed to face the magnetic scale 136. The MR sensor138 reads the magnetic information of the magnetic scale 136 and detectsthe amount of movement (the amount of displacement) of the secondmovable frame 104 including the magnetic scale 136.

The fifth lens group position detection mechanism configured asdescribed above can detect that the fifth lens group G5 is positioned atthe reference position by detecting the light screen 132 with the photointerrupter 134. In addition, the fifth lens group position detectionmechanism can detect the position of the fifth lens group G5 withrespect to the reference position by detecting, with the MR sensor 138,the amount of movement of the fifth lens group G5 that is made after thefifth lens group G5 is positioned at the reference position.

[Installation Position of Magnetic Scale and MR Sensor]

As described above, the MR sensor 138 is disposed to face the magneticscale 136. Therefore, in a case where the installation position of themagnetic scale 136 is determined, the installation position of the MRsensor is also determined.

As shown in FIG. 4 , in the focus unit 100 of the present embodiment,the magnetic scale 136 is disposed at a position that is 90 degrees outof phase with respect to the main shaft 112. That is, in a planeorthogonal to the optical axis Z, the magnetic scale 136 is disposed ona straight line that is orthogonal to a straight line passing throughthe main shaft 112 and the optical axis Z. In other words, the magneticscale 136 is disposed on a position at which a first straight line L1and a third straight line L3 cross at a right angle, the first straightline L1 being a straight line passing through the magnetic scale 136 andthe optical axis Z and the third straight line L3 being a straight linepassing through the main shaft 112 and the optical axis Z in the planeorthogonal to the optical axis Z. Note that, since the MR sensor 138 isdisposed to face the magnetic scale 136, the straight line passingthrough the magnetic scale 136 and the optical axis Z has the samemeaning as a straight line passing through the MR sensor 138 and theoptical axis Z.

Generally, the magnetic scale 136 is provided at the main slidingportion 116 (at the position of the main shaft 112). However, in a casewhere the main sliding portion 116 includes the magnetic scale 136,there is a problem that the diameter of the unit is made large to securean installation space for the MR sensor 138. In the case of the focusunit 100 of the present embodiment, the diameter of the unit can be madesmall since the magnetic scale 136 and the MR sensor 138 are installedto be offset from the main shaft 112. Particularly, in a case where themagnetic scale 136 and the MR sensor 138 are disposed at positions thatare 90 degrees out of phase with respect to the main shaft 112 and thesub shaft 114, as in the case of the focus unit 100 of the presentembodiment, it is possible to dispose the magnetic scale 136 and the MRsensor 138 while effectively using an empty space (a region where amember guiding movement of the second movable frame 104 is not present).Accordingly, the diameter of the unit can be made small.

[Installation Position of Magnetic Force Applying Unit]

As described above, the focus unit 100 according to the presentembodiment includes the four magnetic force applying units 124A to 124D.

FIG. 9 is an explanatory view of the installation positions of the fourmagnetic force applying units.

As shown in the drawing, the four magnetic force applying units 124A to124D are respectively disposed in four compartments separated by thefirst straight line L1 (the straight line passing through the magneticscale 136 and the optical axis Z) and the third straight line L3 (thestraight line passing through the main shaft 112 and the optical axis Z)in the plane orthogonal to the optical axis Z. That is, two magneticforce applying units are disposed on each of both sides separated by thefirst straight line L1 and two magnetic force applying units aredisposed on each of both sides separated by the third straight line L3.

Particularly, in the case of the focus unit 100 of the presentembodiment, the four magnetic force applying units 124A to 124D aredisposed at positions as follows.

That is, as shown in FIG. 9 , the first magnetic force applying unit124A and the second magnetic force applying unit 124B are symmetricallydisposed and the third magnetic force applying unit 124C and the fourthmagnetic force applying unit 124D are symmetrically disposed withrespect to the first straight line L1. Therefore, a disposition angle α1and a disposition angle α2 are equal to each other in a case where astraight line passing through the first magnetic force applying unit124A and the optical axis Z is a straight line S1, a straight linepassing through the second magnetic force applying unit 124B and theoptical axis Z is a straight line S2, an angle formed between thestraight line S1 and the first straight line L1 is the disposition angleα1, and an angle formed between the straight line S2 and the firststraight line L1 is the disposition angle α2. In addition, a dispositionangle α3 and a disposition angle α4 are equal to each other in a casewhere a straight line passing through the third magnetic force applyingunit 124C and the optical axis Z is a straight line S3, a straight linepassing through the fourth magnetic force applying unit 124D and theoptical axis Z is a straight line S4, an angle formed between thestraight line S3 and the first straight line L1 is the disposition angleα3, and an angle formed between the straight line S4 and the firststraight line L1 is the disposition angle α4.

In addition, the first magnetic force applying unit 124A and the fourthmagnetic force applying unit 124D are symmetrically disposed and thesecond magnetic force applying unit 124B and the third magnetic forceapplying unit 124C are symmetrically disposed with respect to the thirdstraight line L3. Therefore, a disposition angle β1 and a dispositionangle β4 are equal to each other in a case where an angle formed betweenthe straight line S1 and the third straight line L3 is the dispositionangle β1, and an angle formed between the straight line S4 and the thirdstraight line L3 is the disposition angle β4. In addition, a dispositionangle β2 and a disposition angle β3 are equal to each other in a casewhere an angle formed between the straight line S2 and the thirdstraight line L3 is the disposition angle β2, and an angle formedbetween the straight line S3 and the third straight line L3 is thedisposition angle β3.

Note that, a straight line passing through the first magnetic forceapplying unit 124A refers to a straight line passing through the centeror the centroid of the first magnetic force applying unit 124A. The sameapplies to the other magnetic force applying units.

For example, in the case of the focus unit 100 of the presentembodiment, the magnetic force applying units 124A to 124D are disposedat positions at which the disposition angles α1, α2, α3, and α4 are 43°and the disposition angles β1, β2, β3, and β4 are 47°.

Note that, in the present embodiment, magnetic force applying unitsdisposed on both sides adjacent to the MR sensor 138 are the firstmagnetic force applying unit 124A and the second magnetic force applyingunit 124B. Therefore, the straight lines S1 and S2 are examples of afourth straight line. In addition, the disposition angles α1 and α2 areexamples of a second angle.

[Installation Posture of Magnetic Force Applying Unit]

The magnetic force applying units 124A to 124D are installed in posturesas follows with respect to the second base frame 102.

FIG. 10 is an explanatory view of the installation postures of themagnetic force applying units.

Regarding each of the magnetic force applying units 124A and 124Bdisposed on both sides adjacent to the MR sensor 138, a straight lineorthogonal to surfaces of the inner yoke portion 128I and the outer yokeportion 128O that face each other will be referred to as a secondstraight line L2. The magnetic force applying units 124A and 124Bdisposed on both sides adjacent to the MR sensor 138 are disposed inpostures in which an angle formed between the first straight line L1 andthe second straight line L2 is smaller than 45°. In other words,disposition is performed such that a normal line from the flat surfaceportion of the magnet 126 from the optical axis Z and a straight linepassing through the optical axis Z and the flat surface portion of themagnet 126 form an angle. Hereinafter, this point will be described inmore detail.

In the focus unit 100 of the present embodiment, the magnetic forceapplying units 124A and 124B disposed on both sides adjacent to the MRsensor 138 are the first magnetic force applying unit 124A and thesecond magnetic force applying unit 124B.

The surfaces of the inner yoke portion 128I and the outer yoke portion128O that face each other are surfaces at which the inner yoke portion128I and the outer yoke portion 128O face the coil 122, and are surfacesparallel to each other. Such a surface is also a surface at which themagnet 126 faces the coil 122. A surface of the inner yoke portion 128Ithat faces the coil 122 will be referred to as a surface 128Ia. Thesecond straight line L2 is a straight line orthogonal to the surface128Ia.

Regarding the first magnetic force applying unit 124A, an angle formedbetween the second straight line L2 and the first straight line L1 willbe referred to as an installation angle θ1. Regarding the secondmagnetic force applying unit 124B, an angle formed between the secondstraight line L2 and the first straight line L1 will be referred to asan installation angle θ2. The installation angles θ1 and 02 are examplesof a first angle.

The first magnetic force applying unit 124A is installed in a posture inwhich the installation angle θ1 is smaller than 45°. Similarly, thesecond magnetic force applying unit 124B is installed in a posture inwhich the installation angle θ2 is smaller than 45°.

In the case of the focus unit 100 of the present embodiment, since thefirst magnetic force applying unit 124A and the second magnetic forceapplying unit 124B are symmetrically disposed with respect to the firststraight line L1, the installation angle θ1 and the installation angleθ2 are angles that are equal to each other (including angles within arange of angles that are acceptable as substantially the same angles aseach other).

For example, in the case of the focus unit 100 of the presentembodiment, the first magnetic force applying unit 124A and the secondmagnetic force applying unit 124B are installed in postures in which theinstallation angles θ1 and θ2 are 35°.

Since the magnetic force applying units 124A and 124B disposed on bothsides adjacent to the MR sensor 138 are installed as described above,the influence of a disturbance magnetic field on the MR sensor 138 canbe suppressed.

FIG. 11 is a graph showing a relationship between the installation angleof a magnetic force applying unit and a magnetic flux density.

The drawing shows the way in which a magnetic flux density in az-direction changes in a case where the installation angles θ1 and θ2 ofthe first magnetic force applying unit 124A and the second magneticforce applying unit 124B are changed within a range of 25° to 55°. Thehorizontal axis represents the installation angles θ1 and θ2 of thefirst magnetic force applying unit 124A and the second magnetic forceapplying unit 124B and the vertical axis represents the magnetic fluxdensity in the z-direction. Here, the z-direction is a directionparallel to the optical axis Z as shown in FIG. 8 . Note that, ay-direction is an inner diameter direction at the installation positionof the MR sensor 138 in a plane orthogonal to the optical axis Z. Inaddition, an x-direction is a tangential direction (a directionorthogonal to the y-direction) at the installation position of the MRsensor 138.

Regarding the MR sensor 138, which is a magnetic sensor, a small amountof position information output is obtained mainly because of theinfluence of a disturbance magnetic field in the z-direction and thex-direction.

As shown in FIG. 11 , it can be found that it is possible to reduce themagnetic flux density (the z-direction) by reducing the installationangles.

Therefore, it is preferable to install the first magnetic force applyingunit 124A and the second magnetic force applying unit 124B such that theinstallation angles θ1 and θ2 are made as small as possible. Asdescribed above, in the present embodiment, the first magnetic forceapplying unit 124A and the second magnetic force applying unit 124B areinstalled in a posture in which the installation angles θ1 and θ2 are35°.

Note that, in the focus unit 100 of the present embodiment, the MRsensor 138 is disposed at a position that is 90 degrees out of phasefrom the main shaft 112 so that compactness in a radial direction isachieved. Meanwhile, the MR sensor 138 is disposed close to the coil122.

FIG. 12 is a graph showing a relationship between a distance between thecoil and the MR sensor and a magnetic field in the z-direction.

In the drawing, the horizontal axis represents a distance between thecoil 122 and the MR sensor 138 in the radial direction and the verticalaxis represents a magnetic field in the z-direction.

As shown in the drawing, as the distance between the coil 122 and the MRsensor 138 increases, the influence of the magnetic field decreases.

Regarding the magnetic force applying units 124A and 124B disposed onboth sides adjacent to the MR sensor 138, the smaller the installationangles θ1 and θ2 thereof are made, the more the distance between thecoil 122 and the MR sensor 138 can be increased. Therefore, making theinstallation angles θ1 and θ2 of the first magnetic force applying unit124A and the second magnetic force applying unit 124B small also resultsin a decrease in influence of the magnetic field of the coil 122.

The installation angles of magnetic force applying units (in the presentembodiment, the third magnetic force applying unit 124C and the fourthmagnetic force applying unit 124D) other than the magnetic forceapplying units on both sides adjacent to the MR sensor 138 are notparticularly limited. In the present embodiment, the third magneticforce applying unit 124C, the fourth magnetic force applying unit 124D,the first magnetic force applying unit 124A, and the second magneticforce applying unit 124B are symmetrically disposed with respect to thethird straight line L3. Therefore, the third magnetic force applyingunit 124C is installed at the same installation angle (including aninstallation angle within a range of installation angles that areacceptable as substantially the same installation angles) as the secondmagnetic force applying unit 124B and the fourth magnetic force applyingunit 124D is installed at the same installation angle (including aninstallation angle within a range of installation angles that areacceptable as substantially the same installation angles) as the firstmagnetic force applying unit 124A.

[Installation Position of MR Sensor]

FIG. 13 is a graph showing a relationship between the installationposition of the MR sensor with respect to the magnetic force applyingunit in the z-direction and the magnetic flux density in thez-direction. In the drawing, the horizontal axis represents theinstallation position of the MR sensor with respect to the magneticforce applying unit in the z-direction, and the vertical axis representsthe magnetic flux density in the z-direction. The reference numeral “ZM”indicates the disposition range of the magnets 126.

FIG. 14 is an explanatory view of the disposition range of the magnetsand the installation position of the MR sensor.

As shown in the drawing, a disposition range ZM of the magnet 126 is arange within which the magnets 126 of the magnetic force applying units124A to 124D attached to the second base frame 102 are disposed in theoptical axis direction (the z-direction).

As shown in FIG. 13 , the closer a position is to the centers of themagnets 126, the smaller the magnetic flux density in the z-direction isat the position. Therefore, the closer the MR sensor 138 is disposed tothe centers of the magnets 126, the less likely the MR sensor 138 isinfluenced by a disturbance magnetic field.

Meanwhile, in a case where the MR sensor 138 is disposed close to thecenters of the magnets 126, the MR sensor 138 protrudes in the opticalaxis direction of the magnetic scale 136 corresponding to closeness,which results in a problem that the degree of freedom in design in theoptical axis direction decrease or the size of a unit in the opticalaxis direction is made large.

Therefore, it is preferable to install the MR sensor 138 inconsideration of the disposition of the magnetic scale 136. In thiscase, it is preferable to install the MR sensor 138 within the range ofthe magnets 126.

In addition, in a case where the MR sensor 138 is installed at aposition distant from the centers of the magnets 126, the influence of adisturbance magnetic field is made large corresponding to distantness.However, in a case where the magnetic force applying units 124A and 124Bdisposed on both sides adjacent to the MR sensor 138 are installed asdescribed above, the influence of the disturbance magnetic field can bereduced.

As described above, regarding the focus unit 100, since the installationangles θ1 and θ2 of the magnetic force applying units 124A and 124Bdisposed on both sides adjacent to the MR sensor 138 are made smallerthan 45°, it is possible to reduce the influence of a disturbancemagnetic field on a sensor and to stably detect the position of thefifth lens group G5, which is a focus lens, with high accuracy.

In addition, since the MR sensor 138 is disposed to be offset from theposition of the main shaft 112, it is possible to make a unit compact indiameter. Particularly, since the MR sensor 138 is disposed at aposition that is 90 degrees out of phase from the main shaft 112, it ispossible to effectively achieve compactness.

In addition, since the MR sensor 138 is disposed at a position that is90 degrees out of phase from the main shaft 112 particularly at anintermediate position between the main shaft 112 and the sub shaft 114,effects as follows can also be achieved. For example, in a case wherethe second base frame 102 is inclined in a plane including the mainshaft 112 and the sub shaft 114 and the MR sensor 138 is disposed at themain shaft 112 or at a position close to the main shaft 112, theinclination causes an error between a lens position on the optical axisand a sensor detection position. Meanwhile, in a case where the MRsensor 138 is disposed at a position that is 90 degrees out of phasefrom the main shaft 112, the influence of inclination can be minimizedeven in a case where there is inclination.

Modification Example of Focus Unit

[About Installation Posture of Magnetic Force Applying Unit]

As described above, the magnetic force applying unit 124A and themagnetic force applying unit 124B disposed on both sides adjacent to theMR sensor 138 are installed in postures in which the installation angles(first angles) θ1 and θ2 thereof are smaller than 45°, more preferably,equal to or smaller than 35°.

[About Installation Position of Magnetic Force Applying Unit]

In the above-described embodiment, the magnetic force applying unit 124Aand the magnetic force applying unit 124B disposed on both sidesadjacent to the MR sensor 138 are disposed at positions at which thedisposition angles (second angles) α1 and α2 thereof are 43°. However,the disposition angles α1 and α2 are not limited thereto. However, inconsideration of compactness of the unit and the like, it is preferablethat the disposition angles α1 and α2 are within a range of equal to orlarger than 35° and smaller than 55°.

In addition, the installation angles (the first angles) θ1 and θ2 of themagnetic force applying unit 124A and the magnetic force applying unit124B disposed on both sides adjacent to the MR sensor 138 are preferablyset to be smaller than the disposition angles (the second angles) α1 andα2 thereof (θ1, θ2<α1, α2).

[About Number of Magnetic Force Applying Units Installed]

In the above-described embodiment, the number of magnetic force applyingunits constituting the voice coil motor 120 is four. However, the numberof magnetic force applying units is not limited thereto. It issufficient that at least two magnetic force applying units are provided.

[Shape of Yoke]

In the above-described embodiment, the shape of each of the inner yokeportions and the outer yoke portions is a rectangular flat plate-likeshape. However, with a configuration as follows, the efficiency of themagnetic force applying units with respect to the volume (mass) of theyokes can be maximized.

FIG. 15 is a contour diagram of the magnetic flux density of themagnetic force applying units. In addition, FIG. 16 is an enlarged viewof a portion of FIG. 15 .

As shown in FIGS. 15 and 16 , the distribution of the magnetic fluxdensity in one magnetic force applying unit is not uniform. The magneticflux density is lowest at the center in the longitudinal direction (theoptical axis direction) and the magnetic flux density increases towardboth ends.

Therefore, in a case where the yokes are configured in accordance withthe distribution of the magnetic flux density, the efficiency of themagnetic force applying units with respect to the volume (mass) of theyokes can be maximized. Specifically, only the width of a portion of ayoke at which the magnetic flux density is high (a portion saturatedwith magnetic flux density) is made large. Meanwhile, the width of aportion of the yoke at which the magnetic flux density is low is madesmall.

FIG. 17 is a perspective view showing an example of a yoke of which thewidth is adjusted in accordance with the distribution of the magneticflux density.

In an example shown in the drawing, in accordance with the distributionof the magnetic flux density of the magnetic force applying unit shownin FIG. 16 , the widths of portions (both end portions) at which themagnetic flux density is high are made large and the width of a portion(the central portion) at which the magnetic flux density is low is madesmall. The efficiency of the magnetic force applying units with respectto the volume (mass) of the yokes can be maximized. In addition,accordingly, the weight of the unit can be reduced.

Note that, in the above-described example, the widths of the yokes areadjusted in accordance with the distribution of the magnetic fluxdensity. However, the same effect can also be achieved throughadjustment of the thicknesses thereof. In addition, both the widths andthe thicknesses can also be adjusted in accordance with the distributionof the magnetic flux density.

[About Magnetic Sensor]

In the above-described embodiment, a case where the MR sensor is used asthe magnetic sensor has been described as an example. However, examplesof the magnetic sensor are not limited thereto. A configuration in whichanother magnetic sensor (for example, a hall sensor or the like) is usedto detect the amount of movement or the position of the fifth lens groupG5 can also be adopted.

[OIS Unit]

A unit based on the first base frame 204 constitutes an OIS unit 200 ofthe interchangeable lens 1. That is, the unit constitutes a camerashake-correction device in the interchangeable lens 1.

FIG. 18 is a perspective view showing a schematic configuration of theOIS unit. FIG. 19 is a front view of the OIS unit shown in FIG. 18 .FIG. 20 is an exploded perspective view of the OIS unit shown in FIG. 18.

In addition, FIG. 21 is a perspective view showing the configuration ofthe first base frame. FIG. 22 is a front view of the first base frame.FIG. 23 is a perspective view showing the configuration of the firstmovable frame. FIG. 24 is a front view of the first movable frame.

The OIS unit 200 includes the first movable frame 202 that is a movablemember holding the second lens group G2 that is a shake-correction lens,the first base frame 204 that is a base member holding the first movableframe 202 such that the first movable frame 202 is movable in a planeorthogonal to the optical axis Z, a drive mechanism that drives thefirst movable frame 202, and a position detection mechanism that detectsthe position of the first movable frame 202.

Note that, the first base frame 204 includes cam pins (not shown) atthree positions on an outer peripheral portion. The cam pins are fittedto a linear movement groove (not shown) that the first fixed cylinder 12includes and a cam groove (not shown) that the cam cylinder 14 includes.Accordingly, in a case where the cam cylinder 14 is rotated, the firstbase frame 204 moves forward and backward along the optical axis Z.

[Holding Structure for First Movable Frame]

The first movable frame 202 is movably held with three rigid balls 206Ato 206C interposed between the first movable frame 202 and the firstbase frame 204. The rigid balls 206A to 206C are examples of rollingbodies. The first base frame 204 includes rigid ball holding portions208A to 208C that respectively hold the rigid balls 206A to 206C. Therigid ball holding portions 208A to 208C are provided at three positionson a circumference around the optical axis. Each of the rigid ballholding portions 208A to 208C is composed of a circular recess portionin which the rigid balls 206A to 206C are rollably accommodated. Thefirst movable frame 202 is pressed to abut the three rigid balls 206A to206C held by the rigid ball holding portions 208A to 208C and issupported to be movable in a plane orthogonal to the optical axis.

Portions of the first movable frame 202 that the rigid balls 206A to206C abut are configured as rigid ball abutment portions and areprovided on a back surface side (the image side) of the first movableframe 202. The rigid ball abutment portion is formed of a surfaceorthogonal to the optical axis, and a metal plate is disposed.

The first movable frame 202 is pressed to abut the rigid balls 206A to206C by being urged toward the first base frame 204 by springs 210 whichare urging members. The springs 210 are provided at three positionsbetween the first movable frame 202 and the first base frame 204. Thefirst base frame 204 includes base-side spring hook portions 212provided at three positions in a circumferential direction. The firstmovable frame 202 includes movable-side spring hook portions 214provided at three positions in the circumferential directioncorresponding to the base-side spring hook portions 212. One end of eachspring 210 is hooked on the base-side spring hook portion 212 and theother end is hooked on the movable-side spring hook portion 214, so thatthe springs 210 are attached between the first movable frame 202 and thefirst base frame 204. Since the springs 210 are attached, the firstmovable frame 202 is urged toward the first base frame 204. As a result,the first movable frame 202 is pressed to abut the rigid balls 206A to206C and is movably held in a plane orthogonal to the optical axis.

A rolling prevention mechanism that prevents the first movable frame 202from rolling is further provided between the first movable frame 202 andthe first base frame 204. Rolling is rotation in a plane orthogonal tothe optical axis. The rolling prevention mechanism is a mechanism thatprevents the first movable frame 202 from rotating in a plane orthogonalto the optical axis.

The rolling prevention mechanism is mainly composed of a swinging block216 which is a swinging member swingably supported by the first baseframe 204, a guide shaft (second shaft) 218 provided at the swingingblock 216, and a sliding portion 220 provided at the first movable frame202.

FIG. 25 is a perspective view showing the configuration of the swingingblock.

The swinging block 216 has a flat block-like shape and includes theguide shaft 218 provided at a distal end thereof.

The swinging block 216 includes a bearing hole (a first hole) 216Aprovided at a proximal end portion. A support shaft (a first shaft) 222is inserted through the bearing hole 216A. The swinging block 216 issupported by the first base frame 204 to be swingable with the supportshaft 222 as an axis.

The first base frame 204 includes a swinging block attachment portion224. As shown in FIGS. 21 and 22 , the swinging block attachment portion224 includes a pair of shaft support portions (first shaft supportportions) 224A. Each of the pair of shaft support portions 224A isconfigured as a plate-shaped protrusion portion and includes a shaftmounting hole (a second hole) 224B that is coaxial with the shaftsupport portion 224A. The support shaft 222 is inserted into the shaftmounting holes 224B and both end portions thereof are supported by theshaft support portions 224A. Accordingly, the support shaft 222 isattached to the swinging block attachment portion 224.

Note that, the support shaft 222 is inserted into the shaft mountingholes 224B of the shaft support portions 224A from an outer peripheralportion of the first base frame 204. Therefore, the outer peripheralportion of the first base frame 204 is provided with support shaftmounting opening portions 226 disposed at positions facing the shaftmounting holes 224B. The support shaft 222 is inserted into the shaftmounting holes 224B of the shaft support portions 224A through thesupport shaft mounting opening portions 226.

The support shaft 222 attached to the swinging block attachment portion224 is disposed to be orthogonal to the optical axis Z. Therefore, theswinging block 216 is supported to be swingable around an axisorthogonal to the optical axis Z.

The guide shaft 218 has a round bar-like shape and is fixed and attachedto a distal end portion of the swinging block 216. Both ends of theguide shaft 218 attached to the swinging block 216 are disposed toproject from both ends of the swinging block 216. Further, the guideshaft 218 attached to the swinging block 216 is disposed to be parallelwith the support shaft 222. Therefore, in a case where the swingingblock 216 is attached to the first base frame 204, the swinging block216 is disposed to be orthogonal to the optical axis Z.

As shown in FIGS. 23 and 24 , the sliding portion 220 includes a pair ofarm portions 220A. Each of the arm portions 220A includes a U-shapedguide groove portion 220B provided at a distal end thereof. The secondlens group G2 is supported to be slidable along the guide shaft 218 withthe guide groove portions 220B fitted to the guide shaft 218.

According to the rolling prevention mechanism configured as describedabove, the first movable frame 202 is supported to be slidable, via thesliding portion 220, with respect to the guide shaft 218 that isswingably supported via the swinging block 216, so that rotation of thefirst movable frame 202 is prevented. Accordingly, the first movableframe 202 is held to be movable in a plane orthogonal to the opticalaxis Z without rolling.

Meanwhile, as shown in FIG. 23 , in the case of the rolling preventionmechanism of the present embodiment, each of the guide groove portions220B of the sliding portion 220 has a shape that is open toward a frontsurface side (the object side) of the first movable frame 202. Adirection in which the guide groove portions 220B are open is adirection in which the first movable frame 202 is separated from thefirst base frame 204 in the optical axis direction. Therefore, in a casewhere the guide shaft 218 is fitted to the guide groove portions 220B,the guide shaft 218 is positioned ahead of the guide groove portions220B (on the object side) as shown in FIGS. 18 and 19 . Since the guideshaft 218 is fitted in such a manner, the guide shaft 218 functions as amember that prevents the first movable frame 202 from falling off. Thatis, the guide shaft 218 has a function of restricting the first movableframe 202 from moving in a direction away from the first base frame 204(in a case where the first movable frame 202 moves in the direction awayfrom the first base frame 204, the guide groove portions 220B abut theguide shaft 218 so that movement in the direction away from the firstbase frame 204 is restricted).

As described above, the rolling prevention mechanism of the presentembodiment not only prevents the first movable frame 202 from rolling,but also has a function of preventing the first movable frame 202 fromfalling off.

Note that, the OIS unit 200 of the present embodiment further includes afall-off prevention pin 228, which is a restricting member, for thepurpose of preventing the first movable frame 202 from falling off.

The fall-off prevention pin 228 is composed of a columnar pin. As shownin FIGS. 18 and 19 , the fall-off prevention pin 228 is attached to aninner peripheral portion of the first base frame 204. On the innerperipheral portion of the first base frame 204, a pin attachment portion230 is provided at a position at which the fall-off prevention pin 228is attached. The pin attachment portion 230 is composed of a recessportion to which a proximal end portion of the fall-off prevention pin228 is fitted. The fall-off prevention pin 228 is attached to the firstbase frame 204 with the proximal end portion fitted to the pinattachment portion 230 and screwed with a screw 232 from an outerperipheral side of the first base frame 204.

The fall-off prevention pin 228 attached to the first base frame 204 isdisposed to project from the inner peripheral portion of the first baseframe 204 in the inner diameter direction.

In addition, the fall-off prevention pin 228 attached to the first baseframe 204 is disposed ahead of the first movable frame 202 mounted tothe first base frame 204 (on the object side). Accordingly, forwardmovement of the first movable frame 202 is restricted by the fall-offprevention pin 228, so that the first movable frame 202 is preventedfrom falling off.

As described above, the OIS unit 200 according to the present embodimentincludes two fall-off prevention mechanisms with respect to the firstmovable frame 202. The two fall-off prevention mechanisms (in otherwords, the rolling prevention mechanism and the fall-off prevention pin228) are disposed at positions (so-called opposite angular positions)facing each other with the optical axis Z interposed therebetween (theswinging block 216 of the rolling prevention mechanism and the fall-offprevention pin 228 are disposed at positions facing each other with theoptical axis Z interposed therebetween). Accordingly, it is possible tomore effectively prevent the first movable frame 202 from falling off

[Drive Mechanism for First Movable Frame]

The first movable frame 202 is driven by two actuators and is moved in afirst direction (a v-direction) and a second direction (an h-direction)in a plane orthogonal to the optical axis Z. The first direction and thesecond direction are directions orthogonal to each other.

In the case of the OIS unit 200 of the present embodiment, two voicecoil motors are used to move the first movable frame 202 in the firstdirection and the second direction. More specifically, the first movableframe 202 is moved in the first direction (v-direction) by a first voicecoil motor 250V which is a first motor and the first movable frame 202is moved in the second direction (h-direction) by a second voice coilmotor 250H which is a second motor.

FIG. 26 is a perspective view showing schematic configurations of thefirst voice coil motor and the second voice coil motor.

The first voice coil motor 250V and the second voice coil motor 250H arecomposed of coils 252V and 252H, magnets 254V and 254H, and yokes 256Vand 256H, respectively.

In the case of the OIS unit 200 of the present embodiment, the coils252V and 252H are provided on the first movable frame 202 on the movableside and the magnets 254V and 254H and the yokes 256V and 256H areattached to the first base frame 204 on a fixed side. That is, in thecase of the OIS unit 200 of the present embodiment, the first voice coilmotor 250V and the second voice coil motor 250H are composed of movingcoil type voice coil motors.

As shown in FIGS. 23 and 24 , the first movable frame 202 includes afirst coil attachment portion 240V to which the coil 252V of the firstvoice coil motor 250V is attached and a second coil attachment portion240H to which the coil 252H of the second voice coil motor 250H isattached.

FIG. 27 is a front view of the first movable frame with the coilsattached thereto.

As shown in the drawing, the coil 252V of the first voice coil motor250V is disposed such that an axis Cv that passes through the center ofan inner periphery (an air-core portion) of the coil 252V passes throughthe optical axis Z and is orthogonal to the optical axis Z. In addition,the coil 252H of the second voice coil motor 250H is disposed such thatan axis Ch that passes through the center of an inner periphery (anair-core portion) of the coil 252H passes through the optical axis Z andis orthogonal to the optical axis Z. Since the coils 252V and 252H aredisposed with respect to the first movable frame 202 such that the axesCv and Ch of the coils 252V and 252H are orthogonal to the optical axisZ as described above, compactness in the radial direction can berealized.

As shown in FIG. 26 , the magnet 254V and the yoke 256V of the firstvoice coil motor 250V are integrated with each other as one unit. Themagnet 254V is composed of a first magnet 254V1 and a second magnet254V2. Each of the first magnet 254V1 and the second magnet 254V2 has ablock-like shape. The yoke 256V is composed of one center yoke (a firstyoke) 256Vc and two side yokes (a second yoke and a third yoke) 256Vs.Each of the center yoke 256Vc and the side yokes 256Vs has a flatplate-like shape and is formed of a magnetic material (for example,iron). The first magnet 254V1 and the second magnet 254V2 are disposedto be respectively interposed between the center yoke 256Vc and the sideyokes 256Vs. The same poles of the first magnet 254V1 and the secondmagnet 254V2 are disposed to face each other. In the present embodiment,the N poles are disposed to face each other (the N poles are disposedclose to the center yoke 256Vc and the S poles are disposed close to theside yokes 256Vs. The magnet 254V and the yoke 256V integrated with eachother form a shape with an E-shaped cross section. That is, the yoke256V is disposed to project from the magnet 254V.

In the present embodiment, the shape of an outer peripheral portion ofthe yoke 256V is an arc shape. Here, the outer peripheral portion is aportion that is disposed on an outer peripheral side of the first baseframe 204 in a case where the yoke 256V is attached to the first baseframe 204. The shape of the outer peripheral portion of the yoke 256V isa shape along an outer periphery of the first base frame 204 (that is,an arc shape). Therefore, in a case where the yoke 256V is attached tothe first base frame 204, the yoke 256V is disposed such that an edgesurface of the outer peripheral portion of the yoke 256V issubstantially flush with the outer periphery of the first base frame204.

The magnet 254H and the yoke 256H of the second voice coil motor 250Halso have the same configurations as described above. That is, themagnet 254H and the yoke 256H are integrated with each other as oneunit. In addition, the magnet 254H is composed of a first magnet 254H1and a second magnet 254H2 and the yoke 256H is composed of one centeryoke (a first yoke) 256Hc and two side yokes (a second yoke and a thirdyoke) 256Hs.

As described above, the magnets 254V and 254H and the yokes 256V and256H are attached to the first base frame 204. As shown in FIGS. 20 and21 , the first base frame 204 includes a first unit attachment portion258V to which the unit composed of the magnet 254V and the yoke 256V ofthe first voice coil motor 250V is attached and a second unit attachmentportion 258H to which the unit composed of the magnet 254H and the yoke256H of the second voice coil motor 250H is attached. The first unitattachment portion 258V is disposed at a position facing the coil 252Vof the first voice coil motor 250V mounted to the first movable frame202 with respect to the first base frame 204 to which the first movableframe 202 is mounted. The second unit attachment portion 258H isdisposed at a position facing the coil 252H of the second voice coilmotor 250H mounted to the first movable frame 202 with respect to thefirst base frame 204 to which the first movable frame 202 is mounted.The first unit attachment portion 258V and the second unit attachmentportion 258H are configured as openings into which the units composed ofthe magnets 254V and 254H and the yokes 256V and 256H are fitted,respectively.

In a case where the unit composed of the magnet 254V and the yoke 256Vis attached to the first unit attachment portion 258V after the firstmovable frame 202 is mounted to the first base frame 204, the centeryoke 256Vc is disposed to be accommodated in a state where the centeryoke 256Vc does not come into contact with an inner peripheral portionof the coil 252V. In addition, a pair of the side yokes 256Vs isdisposed such that an outer periphery of the coil 252V is interposedtherebetween in a state where the outer periphery does not come intocontact with the side yokes 256Vs. Accordingly, in a case where avoltage is applied to the coil 252V, the first movable frame 202 movesin the first direction (the v-direction) in a plane orthogonal to theoptical axis Z.

In addition, in a case where the unit composed of the magnet 254H andthe yoke 256H is attached to the second unit attachment portion 258Hafter the first movable frame 202 is mounted to the first base frame204, a center yoke 256Hc is disposed to be accommodated in a state wherethe center yoke 256Hc does not come into contact with an innerperipheral portion of the coil 252H. In addition, a pair of the sideyokes 256Hs is disposed such that an outer periphery of the coil 252H isinterposed therebetween in a state where the outer periphery does notcome into contact with the side yokes 256Hs. Accordingly, in a casewhere a voltage is applied to the coil 252H, the first movable frame 202moves in the second direction (the h-direction) in a plane orthogonal tothe optical axis Z.

The drive mechanism of the first movable frame 202 is configured asdescribed above. The first movable frame 202 moves in the firstdirection (the v-direction) in a plane orthogonal to the optical axis Zin a case where the first voice coil motor 250V is driven. In addition,the first movable frame 202 moves in the second direction (theh-direction) in a plane orthogonal to the optical axis Z in a case wherethe second voice coil motor 250H is driven.

Meanwhile, in the case of the drive mechanism of the present embodiment,the coils 252V and 252H of the voice coil motors are disposed such thatthe axes Cv and Ch are orthogonal to the optical axis Z, so thatcompactness in the radial direction is realized.

However, in a case where the coils 252V and 252H are disposed in such amanner, the yokes 256V and 256H are disposed to collide with the coils252V and 252H in a case where the first movable frame 202 falls off.Particularly, the center yokes 256Vc and 256Hc disposed on innerperipheral portions of the yokes 256V and 256H are disposed to collidewith the inner peripheral portions of the coils 252V and 252H.

However, in the case of the OIS unit 200 of the present embodiment, asdescribed above, the fall-off prevention mechanisms are provided withrespect to the first movable frame 202. Therefore, there is noprobability that the first movable frame 202 falls off and the OIS unit200 can be used safely. Particularly, in the case of the OIS unit 200 ofthe present embodiment, the rolling prevention mechanism also serves asthe fall-off prevention mechanism. Therefore, it is possible to preventthe first movable frame 202 from falling off without increasing thenumber of components.

[Position Detection Mechanism of First Movable Frame]

The position of the first movable frame 202 in the first direction (thev-direction) and the position of the first movable frame 202 in thesecond direction (the h-direction) are detected based on a point atwhich the second lens group G2 is positioned on the optical axis Z. Theposition in the first direction is detected by a first positiondetection sensor 260V. The position in the second direction is detectedby a second position detection sensor 260H. In the OIS unit 200 of thepresent embodiment, both the first position detection sensor 260V andthe second position detection sensor 260H are composed of hall sensors(hall elements). The hall sensor is a magnetic sensor and detects theposition of an object in combination with a position detection magnet.In the OIS unit 200 of the present embodiment, the first base frame 204includes the first position detection sensor 260V and the secondposition detection sensor 260H composed of the hall sensors and thefirst movable frame 202 includes position detection magnets 262V and262H. Note that, the position detection magnet 262V for the firstposition detection sensor 260V will be referred to as the first positiondetection magnet 262V, and the position detection magnet 262H for thesecond position detection sensor 260H will be referred to as the secondposition detection magnet 262H so that the position detection magnetsare distinguished from each other.

As shown in FIG. 22 , the first base frame 204 includes a first positiondetection sensor attachment portion 264V provided at a position at whichthe first position detection sensor 260V is installed and a secondposition detection sensor attachment portion 264H provided at a positionat which the second position detection sensor 260H is installed. Thefirst position detection sensor attachment portion 264V is composed of arectangular opening portion and the first position detection sensor 260Vis positioned and attached with the first position detection sensor 260Vfitted to the opening portion. Similarly, the second position detectionsensor attachment portion 264H is composed of a rectangular openingportion and the second position detection sensor 260H is positioned andattached with the second position detection sensor 260H fitted to theopening portion.

The first position detection sensor 260V is disposed on a v-axis bybeing attached to the first position detection sensor attachment portion264V. The v-axis is an axis that passes through the optical axis Z andis parallel to the first direction (the v-direction). In addition, thefirst position detection sensor 260V is attached to the first positiondetection sensor attachment portion 264V, so that the first positiondetection sensor 260V is disposed at a position facing the first voicecoil motor 250V with the optical axis Z interposed therebetween.

The second position detection sensor 260H is disposed on an h-axis bybeing attached to the second position detection sensor attachmentportion 264H. The h-axis is an axis that passes through the optical axisZ and is parallel to the second direction (the h-direction). Inaddition, the second position detection sensor 260H is attached to thesecond position detection sensor attachment portion 264H, so that thesecond position detection sensor 260H is disposed at a position facingthe second voice coil motor 250H with the optical axis Z interposedtherebetween.

As shown in FIG. 24 , each of the first position detection magnet 262Vand the second position detection magnet 262H is attached to the firstmovable frame 202. The positions of attachment are positions facing thefirst position detection sensor 260V and the second position detectionsensor 260H with certain gaps provided therebetween in a case where thefirst movable frame 202 is mounted to the first base frame 204. Morespecifically, the first position detection magnet 262V is disposed at aposition that coincides with (including a range of positionssubstantially coinciding with) the center of the first positiondetection sensor 260V in a case where the second lens group G2 ispositioned on the optical axis Z. In addition, the second positiondetection magnet 262H is disposed at a position that coincides with thecenter of the second position detection sensor 260H in a case where thesecond lens group G2 is positioned on the optical axis Z.

According to the above-described configuration, in a case where thefirst movable frame 202 moves in the first direction (the v-direction),the position thereof (the position thereof in the first direction withrespect to the optical axis Z) is detected by the first positiondetection sensor 260V. In addition, in a case where the first movableframe 202 moves in the second direction (the h-direction), the positionthereof (the position thereof in the second direction with respect tothe optical axis Z) is detected by the second position detection sensor260H.

[Disposition of Rigid Ball Holding Portions]

As described above, in the OIS unit 200 of the present embodiment, thefirst movable frame 202 is movably held by the first base frame 204 viathe three rigid balls 206A to 206C. The three rigid balls 206A to 206Care held by the three rigid ball holding portions 208A to 208C that thefirst base frame 204 includes. In the related art, the rigid ballholding portions 208A to 208C are disposed on the same cross sectionorthogonal to the optical axis Z. That is, in the related art, the rigidball holding portions 208A to 208C are disposed at positions that areseparated from an edge surface of the first base frame 204 by the samedistance in the optical axis direction.

Meanwhile, in the case of the OIS unit 200 of the present embodiment,the three rigid ball holding portions 208A to 208C are disposed atdifferent positions for realization of compactness. Specifically, asshown in FIG. 21 , two of the three rigid ball holding portions 208A to208C are disposed at the same cross-sectional position (the position ofa cross section orthogonal to the optical axis Z), and the remaining oneof the three rigid ball holding portions 208A to 208C is disposed at adifferent cross-sectional position.

Hereinafter, the rigid ball holding portion 208A will be referred to asthe first rigid ball holding portion 208A, the rigid ball holdingportion 208B will be referred to as the second rigid ball holdingportion 208B, and the rigid ball holding portion 208C will be referredto as the third rigid ball holding portion 208C so that the three rigidball holding portions 208A to 208C are distinguished from each other,and the disposition thereof will be described.

As shown in FIG. 22 , the first rigid ball holding portion 208A is arigid ball holding portion disposed close to the first positiondetection sensor attachment portion 264V. In addition, the second rigidball holding portion 208B is a rigid ball holding portion that isdisposed close to the second position detection sensor attachmentportion 264H.

Here, in a case where the rigid ball holding portions and the positiondetection sensor attachment portions are disposed close to each other,there is a problem as follows. That is, there is a problem that therigid ball abutment portions provided on the first movable frame 202side come into contact with the position detection sensor attachmentportions in a case where the first movable frame 202 is driven. In orderto avoid such a problem, it is necessary to secure a sufficient distancebetween the rigid ball holding portions and the position detectionsensor attachment portions. However, in a case where a sufficientdistance is secured between the rigid ball holding portions and theposition detection sensor attachment portions, there is a problem thatthe size of the unit is made large.

Therefore, in the case of the OIS unit 200 of the present embodiment,the rigid ball holding portions that are disposed close to the positiondetection sensor attachment portions are disposed at the samecross-sectional positions as the position detection sensor attachmentportions. That is, as shown in FIG. 22 , the first rigid ball holdingportion 208A and the second rigid ball holding portion 208B are disposedat the same cross-sectional positions as the first position detectionsensor attachment portion 264V and the second position detection sensorattachment portion 264H. Even in a case where the position detectionsensor attachment portions and the rigid ball holding portions aredisposed close to each other, it is possible to prevent the rigid ballabutment portions from coming into contact with the position detectionsensor attachment portions.

On the other hand, the third rigid ball holding portion 208C is disposedbetween the first voice coil motor 250V and the second voice coil motor250H in a cross section orthogonal to the optical axis Z. In order todispose the third rigid ball holding portion 208C at the samecross-sectional position as the first rigid ball holding portion 208Aand the second rigid ball holding portion 208B, it is necessary to shiftthe positions of the first voice coil motor 250V and the second voicecoil motor 250H in the optical axis direction. However, in a case wherethe positions of the first voice coil motor 250V and the second voicecoil motor 250H are shifted in the optical axis direction, there is aproblem that size of the unit is made large in the optical axisdirection.

Therefore, the third rigid ball holding portion 208C is disposed at across-sectional position different from those of the first rigid ballholding portion 208A and the second rigid ball holding portion 208B.

FIG. 28 is an explanatory view of a relationship between the dispositionof the first rigid ball holding portion and the disposition of the thirdrigid ball holding portion. In the drawing, the upper part shows a crosssection showing the installation position of the first rigid ballholding portion 208A, and the lower part shows a cross section showingthe installation position of the third rigid ball holding portion 208C.

As shown in the figure, the first rigid ball holding portion 208A isdisposed on the object side which is ahead of the third rigid ballholding portion 208C. Such a position is the same as the cross-sectionalposition of the first position detection sensor attachment portion 264V.In addition, the second rigid ball holding portion 208B is disposed atthe same cross-sectional position as the first rigid ball holdingportion 208A.

As described above, in the case of the OIS unit 200 of the presentembodiment, the disposition of the three rigid ball holding portions208A to 208C in the optical axis direction is adjusted so thatcompactness of the unit is realized.

Note that, in the present embodiment, a configuration in which the firstposition detection sensor attachment portion 264V and the secondposition detection sensor attachment portion 264H are disposed at thesame cross-sectional position. However, a configuration in which thefirst position detection sensor attachment portion 264V and the secondposition detection sensor attachment portion 264H are disposed atdifferent cross-sectional positions may also be adopted. In this case,the rigid ball holding portions that are disposed close to therespective position detection sensor attachment portions are disposedsuch that a rigid ball holding portion is disposed at the samecross-sectional position as a position detection sensor attachmentportion corresponding thereto. Note that, the meaning of the samecross-sectional positions includes a range of cross-sectional positionsacceptable as substantially the same cross-sectional positions.

[Disposition of Flexible Printed Circuit]

As described above, in the OIS unit 200 of the present embodiment, thefirst movable frame 202 is driven by the moving coil type voice coilmotors. In this case, supply of power to the coils is performed by meansof flexible printed circuits (FPCs). The flexible printed circuits aredisposed while being bent such that the driving of the first movableframe 202 is not influenced.

In the case of the OIS unit 200 in the related art, power is supplied tothe two voice coil motors by means of a common flexible printed circuit.

However, in the case of a configuration in which power is supplied tothe two voice coil motors by means of the common flexible printedcircuit, there is a problem that the degree of freedom in designingother constituent elements is lowered, which results in an increase insize of the unit.

Therefore, in the case of the OIS unit 200 of the present embodiment,power is supplied to the two voice coil motors by means of differentflexible printed circuits. That is, the flexible printed circuits areseparately disposed with respect to the two voice coil motors.

Specifically, as shown in FIG. 27 , supply of power to the coil 252V ofthe first voice coil motor 250V is performed by means of a firstflexible printed circuit 270V. Meanwhile, supply of power to the coil252H of the second voice coil motor 250H is performed by means of asecond flexible printed circuit 270H different from the first flexibleprinted circuit 270V.

FIG. 29 is a perspective view showing the configurations of the firstflexible printed circuit and the second flexible printed circuit. Inaddition, FIG. 30 is a front view showing the configurations of thefirst flexible printed circuit and the second flexible printed circuit.

As shown in FIG. 29 , the first flexible printed circuit 270V includes afixed portion 270Va, a first linear portion 270Vb that extends forward(to the object side) along the optical axis direction from the fixedportion 270Va, an arc-shaped bent portion 270Vc that extends in adirection orthogonal to the optical axis from a distal end of the firstlinear portion 270Vb, and a second linear portion 270Vd that extendsrearward (to the object side) along the optical axis from a distal endof the bent portion 270Vc.

Similarly, the second flexible printed circuit 270H includes a fixedportion 270Ha, a first linear portion 270Hb that extends forward (to theobject side) along the optical axis direction from the fixed portion270Ha, an arc-shaped bent portion 270Hc that extends in a directionorthogonal to the optical axis from a distal end of the first linearportion 270Hb, and a second linear portion 270Hd that extends rearward(to the object side) along the optical axis from a distal end of thebent portion 270Hc.

The fixed portions 270Va and 270Ha are portions that are fixed andattached to the first movable frame 202. As shown in FIG. 30 , the firstmovable frame 202 includes a first flexible printed circuit attachmentportion 272V for attachment of the fixed portion 270Va of the firstflexible printed circuit 270V and a second flexible printed circuitattachment portion 272H for attachment of the fixed portion 270Ha of thesecond flexible printed circuit 270H. The first flexible printed circuitattachment portion 272V is provided in the vicinity of the installationposition of the coil 252V of the first voice coil motor 250V. The secondflexible printed circuit attachment portion 272H is disposed in thevicinity of the installation position of the coil 252H of the secondvoice coil motor 250H.

The bent portion 270Vc of the first flexible printed circuit 270Vattached to the first movable frame 202 is disposed at a position (aso-called opposite angular position) facing the coil 252H of the secondvoice coil motor 250H with the optical axis Z interposed therebetween.Meanwhile, the bent portion 270Hc of the second flexible printed circuit270H is disposed at a position (a so-called opposite angular position)facing the coil 252V of the first voice coil motor 250V with the opticalaxis Z interposed therebetween.

In addition, the respective bent portions 270Vc and 270Hc of the firstflexible printed circuit 270V and the second flexible printed circuit270H attached to the first movable frame 202 are disposed while beingbent in directions orthogonal to the optical axis Z. Accordingly, themovement of the first movable frame 202 can be absorbed.

As described above, in the case of the OIS unit 200 of the presentembodiment, power is supplied to the two voice coil motors by means ofdifferent flexible printed circuits. Accordingly, a degree of freedom indesigning the unit can be ensured, and thus compactness of the unit canbe realized.

Note that, although the bent portions 270Vc and 270Hc are bent in thedirections orthogonal to the optical axis Z in the present embodiment, aconfiguration in which the bent portions 270Vc and 270Hc are bent in theoptical axis direction may also be adopted. In this case as well, thesame effect can be achieved.

[Assembly of OIS Unit]

The OIS unit 200 according to the present embodiment is assembledthrough a procedure as follows.

First, the fifth lens group G5, the coil 252V of the first voice coilmotor 250V, the coil 252H of the second voice coil motor 250H, the firstflexible printed circuit 270V, and the second flexible printed circuit270H are mounted to the first movable frame 202. The coil 252V of thefirst voice coil motor 250V is electrically connected to the firstflexible printed circuit 270V via the fixed portion 270Va of the firstflexible printed circuit 270V since the first flexible printed circuit270V is mounted to the first movable frame 202. In addition, the coil252H of the second voice coil motor 250H is electrically connected tothe second flexible printed circuit 270H via the fixed portion 270Va ofthe second flexible printed circuit 270H since the second flexibleprinted circuit 270H is mounted to the first movable frame 202.

Next, the first movable frame 202 to which a lens or the like isattached is mounted to the first base frame 204. In the assembly of thefirst movable frame 202, first, the rigid balls 206A to 206C areattached to the three rigid ball holding portions 208A to 208C. Next,the first movable frame 202 is mounted to the first base frame 204 suchthat the rigid balls 206A to 206C are interposed therebetween. Next, thesprings 210 are mounted between the first movable frame 202 and thefirst base frame 204 and the first movable frame 202 and the first baseframe 204 are integrated with each other. Accordingly, the first movableframe 202 is held to be movable with respect to the first movable frame202.

Next, the swinging block 216 is attached to the first base frame 204.The swinging block 216 is attached to the swinging block attachmentportion 224 that the first base frame 204 includes. The attachment isperformed from the front surface side (the object side) of the firstbase frame 204. In this case, the guide shaft 218 provided at the distalend of the swinging block 216 is fitted to the guide groove portions220B of the sliding portion 220 that the first movable frame 202includes. Thereafter, the support shaft 222 is inserted through thebearing hole (the second hole) 216A provided at the proximal end portionof the swinging block 216 and the shaft mounting holes 224B provided atthe pair of shaft support portions 224A of the swinging block attachmentportion 224 so that the swinging block 216 is integrated with the firstbase frame 204. Thereby, the swinging block 216 is supported to beswingable with the support shaft 222 as an axis. The support shaft 222is mounted through the support shaft mounting opening portions 226provided at the outer peripheral portion of the first base frame 204.

Since the swinging block 216 is attached, the first base frame 204 isrestricted from rolling. In addition, the first base frame 204 is alsoprevented from falling off. That is, the guide shaft 218 restrictsmovement in the optical axis direction to prevent the first base frame204 from falling off.

Next, the fall-off prevention pin 228 is attached to the first baseframe 204. The fall-off prevention pin 228 is positioned at apredetermined position with the proximal end portion thereof fitted tothe pin attachment portion 230 provided at the first base frame 204. Thepositioned fall-off prevention pin 228 is screwed with the screw 232from the outer peripheral side of the first base frame 204 so that thefall-off prevention pin 228 is fixed. The fall-off prevention pin 228attached to the first base frame 204 is disposed ahead of the first baseframe 204 (on the object side) and restricts the forward movement of thefirst movable frame 202 in the optical axis direction to prevent thefirst base frame 204 from falling off.

Next, the units composed of the magnets 254V and 254H and the yokes 256Vand 256H of the first voice coil motor 250V and the second voice coilmotor 250H are attached to the first base frame 204. The unit composedof the magnet 254V and the yoke 256V of the first voice coil motor 250Vis attached to the first unit attachment portion 258V of the first baseframe 204. In addition, the unit composed of the magnet 254H and theyoke 256H of the second voice coil motor 250H is attached to the secondunit attachment portion 258H of the first base frame 204.

Since the unit composed of the magnet 254V and the yoke 256V of thefirst voice coil motor 250V is attached to the first unit attachmentportion 258V, the center yoke 256Vc is disposed to be accommodated inthe inner peripheral portion of the coil 252V on the first movable frame202 side. In addition, the pair of side yokes 256Vs is disposed suchthat the outer periphery of the coil 252V is interposed therebetween. Inaddition, since the unit composed of the magnet 254H and the yoke 256Hof the second voice coil motor 250H is attached to the second unitattachment portion 258H, the center yoke 256Hc is disposed to beaccommodated in the inner peripheral portion (the air-core portion) ofthe coil 252H on the first movable frame 202 side. In addition, the pairof the side yokes 256Hs is disposed such that the outer periphery of thecoil 252H is interposed.

As a result, the assembly of the OIS unit 200 is finished.

Modification Example of OIS Unit Modification Example of Voice CoilMotor

In the above-described embodiment, the voice coil motors are disposed inpostures in which the axes of the coils are orthogonal to the opticalaxis. However, the voice coil motors may be disposed in postures inwhich the axes of the coils are parallel to the optical axis. However,for realization of compactness (particularly, compactness in the radialdirection) of the unit, it is preferable that the voice coil motors aredisposed in postures in which the axes of the coils are orthogonal tothe optical axis as in the case of the OIS unit 200 in theabove-described embodiment.

Modification Example of Unit Composed of Yoke and Magnet

FIG. 31 is a perspective view of a modification example of the unitcomposed of the magnet and the yoke.

In the case of the OIS unit 200 according to the embodiment describedabove, the shapes of the outer peripheral portions (portions that arepositioned on an outer peripheral side in the case of attachment to thefirst base frame 204) of the yokes 256V and 256H are arc shapes alongthe shape of the outer periphery of the first base frame 204.

As shown in FIG. 31 , it is preferable that the outer peripheralportions of the magnets 254V and 254H also have arc shapes. That is, itis preferable that portions that are positioned on the outer peripheralside in the case of attachment to the first base frame 204 have arcshapes along the shape of the outer periphery of the first base frame204. Accordingly, thrust can be increased without a change in unit size.

FIG. 32 is a graph about comparison between a Lorentz force generated ina case where the shapes of the outer peripheral portions of the magnetsare linear shapes and a Lorentz force generated in a case where theshapes of the outer peripheral portions of the magnets are arc shapes.In the drawing, the horizontal axis represents a stroke and the verticalaxis represents a Lorentz force.

The reference numeral “Ls” represents a graph about a Lorentz forcegenerated in a case where the shapes of the outer peripheral portions ofthe magnets are linear shapes. The reference numeral “La” represents agraph about a Lorentz force generated in a case where the shapes of theouter peripheral portions of the magnets are arc shapes.

As shown in the drawing, by forming the outer peripheral portions of themagnets in arc shapes, it is possible to increase thrust in comparisonwith a case where the outer peripheral portions have linear shapes.

Since the outer peripheral portions of the magnets are formed in arcshapes, edge surfaces of the outer peripheral portions of the magnetsare disposed to be substantially flush with the outer periphery of thefirst base frame 204 in a case where the magnets are attached to thefirst base frame 204.

Other Embodiments

[Application to Other Optical Devices]

In the above-described embodiment, a case where the present invention isapplied to a lens barrel of an interchangeable lens of aninterchangeable lens camera has been described as an example. However,the application of the present invention is not limited thereto. Thepresent invention can also be applied to a lens barrel of anintegrated-lens camera. Examples of the camera include various camerassuch as a silver halide camera, a video camera, a cine-camera, a TVcamera, and a surveillance camera in addition to a digital camera. Inaddition, the camera is not limited to a camera configured as a singlecamera and examples thereof also include a camera incorporated intoanother device such as a smartphone or a personal computer. The presentinvention can also be applied to a lens barrel of an optical device suchas a microscope or a telescope instead of the camera.

[Application to Image Sensor Shifting Type Camera Shake-CorrectionMechanism]

The technology related to the OIS unit can also be applied to an imagesensor shifting type camera shake-correction mechanism. The image sensorshifting type camera shake-correction mechanism is a mechanism in whichan image sensor (an imaging element) is moved in accordance with acamera shake so that camera shake correction is performed.

[Appendix]

Furthermore, appendixes as follows will be disclosed in relation to theabove-described embodiment.

(Appendix 1)

A camera shake-correction device including:

a movable member that holds a camera shake-correction lens or an imagesensor;

a base member that supports the movable member such that the movablemember is movable in a plane orthogonal to an optical axis;

a plurality of rolling bodies that are provided between the movablemember and the base member;

an urging member that urges the base member toward the movable member;

a first motor that drives the movable member in a first direction in theplane orthogonal to the optical axis;

a second motor that drives the movable member in a second directionorthogonal to the first direction in the plane orthogonal to the opticalaxis;

a first shaft that is provided at the movable member and that isdisposed to be orthogonal to the optical axis;

a swinging member of which a proximal end portion is swingably supportedby the first shaft;

a second shaft that is provided at a distal end portion of the swingingmember and that is disposed to be parallel with the first shaft;

a sliding portion that is provided at the movable member and that slidesalong the second shaft; and

a restricting member that is provided at the base member and thatrestricts movement of the movable member in a direction away from thebase member;

in which the sliding portion includes a groove portion that is open in adirection in which the movable member is separated from the base member,and

the second shaft is fitted to the groove portion and is slidablysupported.

(Appendix 2)

The camera shake-correction device described in Appendix 1,

in which the first motor and the second motor are composed voice coilmotors including coils, magnets, and yokes,

the coils are provided at the movable member, and

the magnets and the yokes are provided at the base member.

(Appendix 3)

The camera shake-correction device described in Appendix 2,

in which the coil is disposed such that an axis of the coil isorthogonal to the optical axis.

(Appendix 4)

The camera shake-correction device described in Appendix 3,

in which a portion of the yoke is disposed inside the coil.

(Appendix 5)

The camera shake-correction device described in Appendix 4,

in which the magnet is composed of a first magnet and a second magnet ofwhich the same poles are disposed to face each other,

the yoke is composed of a first yoke, a second yoke, and a third yoke,

the first magnet is disposed between the first yoke and the second yoke,

the second magnet is disposed between the second yoke and the thirdyoke, and

the second yoke is disposed inside the coil.

(Appendix 6)

The camera shake-correction device described in any one of Appendixes 3to 5,

in which shapes of outer peripheries of the magnet and the yoke in theplane orthogonal to the optical axis are arc shapes along a circlearound the optical axis.

(Appendix 7)

The camera shake-correction device described in any one of Appendixes 2to 6, further including:

a first flexible printed circuit connected to the coil of the firstmotor; and

a second flexible printed circuit connected to the coil of the secondmotor,

in which the first flexible printed circuit and the second flexibleprinted circuit are separately disposed.

(Appendix 8)

The camera shake-correction device described in Appendix 7,

in which the first flexible printed circuit is disposed while being bentat a position facing the second motor with the optical axis interposedtherebetween in the plane orthogonal to the optical axis, and

the second flexible printed circuit is disposed while being bent at aposition facing the first motor with the optical axis interposedtherebetween in the plane orthogonal to the optical axis.

(Appendix 9)

The camera shake-correction device described in Appendix 8,

in which the first flexible printed circuit and the second flexibleprinted circuit are disposed while being bent in directions orthogonalto the optical axis.

(Appendix 10)

The camera shake-correction device described in any one of Appendixes 1to 9,

in which the base member includes a pair of first shaft support portionsprovided with first holes,

both end portions of the first shaft is inserted into the first holes sothat the first shaft is held by the first shaft support portion,

the proximal end portion of the swinging member includes a second holethrough which the first shaft is inserted, and

and the swinging member is swingably supported by the first shaft withthe first shaft inserted through the second hole.

(Appendix 11)

The camera shake-correction device described in any one of Appendixes 1to 10,

in which the swinging member and the restricting member are disposed atpositions facing each other with the optical axis interposedtherebetween in the plane orthogonal to the optical axis.

(Appendix 12)

The camera shake-correction device described in Appendix 1,

in which at least one of the rolling bodies is disposed at a positiondifferent from positions of the other rolling bodies in a directionalong the optical axis.

(Appendix 13)

The camera shake-correction device described in Appendix 12, furthercomprising:

a first position detection sensor that detects a position of the movablemember with respect to the base member in the first direction; and

a second position detection sensor that detects a position of themovable member with respect to the base member in the second direction,

in which the rolling body disposed close to the first position detectionsensor and the rolling body disposed close to the second positiondetection sensor are disposed at positions different from a position ofthe other rolling body.

(Appendix 14)

A camera shake-correction device including:

a movable member that holds a camera shake-correction lens or an imagesensor;

a base member that supports the movable member such that the movablemember is movable in a plane orthogonal to an optical axis;

a plurality of rolling bodies that are provided between the movablemember and the base member;

an urging member that urges the base member toward the movable member;

a first motor that is composed of a voice coil motor including a coil, amagnet, and a yoke and that drives the movable member in a firstdirection in the plane orthogonal to the optical axis; and

a second motor that is composed of a voice coil motor including a coil,a magnet, and a yoke and that drives the movable member in a seconddirection orthogonal to the first direction in the plane orthogonal tothe optical axis,

in which the first motor and the second motor are disposed such thataxes of the coils are orthogonal to the optical axis, and

portions of the yokes are disposed inside the coils.

(Appendix 15)

The camera shake-correction device described in Appendix 14,

in which the magnet is composed of a first magnet and a second magnet ofwhich the same poles are disposed to face each other,

the yoke is composed of a first yoke, a second yoke, and a third yoke,

the first magnet is disposed between the first yoke and the second yoke,

the second magnet is disposed between the second yoke and the thirdyoke, and

the second yoke is disposed inside the coil.

(Appendix 16)

The camera shake-correction device described in any one of Appendixes 14to 15,

in which shapes of outer peripheries of the magnet and the yoke in theplane orthogonal to the optical axis are arc shapes along a circlearound the optical axis.

(Appendix 17)

A camera shake-correction device including:

a movable member that holds a camera shake-correction lens or an imagesensor;

a base member that supports the movable member such that the movablemember is movable in a plane orthogonal to an optical axis;

a plurality of rolling bodies that are provided between the movablemember and the base member;

an urging member that urges the base member toward the movable member;

a first motor that is composed of a voice coil motor including a coil, amagnet, and a yoke and that drives the movable member in a firstdirection in the plane orthogonal to the optical axis;

a second motor that is composed of a voice coil motor including a coil,a magnet, and a yoke and that drives the movable member in a seconddirection orthogonal to the first direction in the plane orthogonal tothe optical axis;

a first flexible printed circuit connected to the coil of the firstmotor; and

a second flexible printed circuit connected to the coil of the secondmotor,

in which the first flexible printed circuit and the second flexibleprinted circuit are separately disposed.

(Appendix 18)

The camera shake-correction device according to Appendix 17,

in which the first flexible printed circuit is disposed while being bentat a position facing the second motor with the optical axis interposedtherebetween in the plane orthogonal to the optical axis, and

the second flexible printed circuit is disposed while being bent at aposition facing the first motor with the optical axis interposedtherebetween in the plane orthogonal to the optical axis.

(Appendix 19)

The camera shake-correction device according to Appendix 18,

in which the first flexible printed circuit and the second flexibleprinted circuit are disposed while being bent in directions orthogonalto the optical axis.

(Appendix 20)

A camera shake-correction device including:

a movable member that holds a camera shake-correction lens or an imagesensor;

a base member that supports the movable member such that the movablemember is movable in a plane orthogonal to an optical axis;

a plurality of rolling bodies that are provided between the movablemember and the base member;

an urging member that urges the base member toward the movable member;

a first motor that drives the movable member in a first direction in theplane orthogonal to the optical axis; and

a second motor that drives the movable member in a second directionorthogonal to the first direction in the plane orthogonal to the opticalaxis,

in which at least one of the rolling bodies is disposed at a positiondifferent from positions of the other rolling bodies in a directionalong the optical axis.

(Appendix 21)

The camera shake-correction device according to Appendix 20, furthercomprising:

a first position detection sensor that detects a position of the movablemember with respect to the base member in the first direction; and

a second position detection sensor that detects a position of themovable member with respect to the base member in the second direction,

in which the rolling body disposed close to the first position detectionsensor and the rolling body disposed close to the second positiondetection sensor are disposed at positions different from a position ofthe other rolling body.

EXPLANATION OF REFERENCES

-   -   1: interchangeable lens    -   2: mount    -   3: focus ring    -   4: zoom ring    -   5: stop ring    -   10: lens barrel    -   12: first fixed cylinder    -   14: cam cylinder    -   16: moving cylinder    -   18: second fixed cylinder    -   20: mount base member    -   22: first lens group holding frame    -   24: seventh lens group holding frame    -   30: stop unit    -   100: focus unit    -   102: second base frame    -   102F: second base frame front frame    -   102R: second base frame rear frame    -   104: second movable frame    -   106: third lens group holding portion    -   108: fourth lens group holding portion    -   110: sixth lens group holding portion    -   112: main shaft    -   114: sub shaft    -   116: main sliding portion    -   116A: hole of main sliding portion    -   118: sub sliding portion    -   118A: groove of sub sliding portion    -   120: voice coil motor    -   122: coil of voice coil motor    -   124A to 124D: magnetic force applying unit of voice coil motor    -   124A: first magnetic force applying unit of voice coil motor    -   124B: second magnetic force applying unit of voice coil motor    -   124C: third magnetic force applying unit of voice coil motor    -   124D: fourth magnetic force applying unit of voice coil motor    -   126: magnet of voice coil motor    -   128: yoke of voice coil motor    -   128I: inner yoke portion of yoke    -   128Ia: surfaces facing coil at inner yoke portion    -   128O: outer yoke portion of yoke    -   130A to 130D: magnetic force applying unit holding portions    -   132: light screen    -   134: photo interrupter    -   136: magnetic scale    -   138: MR sensor    -   200: OIS unit    -   202: first movable frame    -   204: first base frame    -   206A: rigid ball    -   206B: rigid ball    -   206C: rigid ball    -   208A to 208C: rigid ball holding portion    -   208A: first rigid ball holding portion    -   208B: second rigid ball holding portion    -   208C: third rigid ball holding portion    -   210: spring    -   212: base-side spring hook portion    -   214: movable-side spring hook portion    -   216: swinging block    -   216A: bearing hole of swinging block    -   218: guide shaft    -   220: sliding portion of first movable frame    -   220A: arm portion of sliding portion    -   220B: guide groove portion of sliding portion    -   222: support shaft    -   224: swinging block attachment portion    -   224A: shaft support portion    -   224B: shaft mounting hole of shaft support portion    -   226: support shaft mounting opening portion    -   228: fall-off prevention pin    -   230: pin attachment portion    -   232: screw    -   240V: first coil attachment portion    -   240H: second coil attachment portion    -   250V: first voice coil motor    -   250H: second voice coil motor    -   252V: coil of first voice coil motor    -   252H: coil of second voice coil motor    -   254V: magnet of first voice coil motor    -   254V1: first magnet of first voice coil motor    -   254V2: second magnet of first voice coil motor    -   254H: magnet of second voice coil motor    -   254H1: first magnet of second voice coil motor    -   254H2: second magnet of second voice coil motor    -   256V: yoke of first voice coil motor    -   256Vc: center yoke of first voice coil motor    -   256Vs: side yoke of first voice coil motor    -   256H: yoke of second voice coil motor    -   256Hc: center yoke of second voice coil motor    -   256Hs: side yoke of second voice coil motor    -   258V: first unit attachment portion    -   258H: second unit attachment portion    -   260V: first position detection sensor    -   260H: second position detection sensor    -   262H, 262V: position detection magnet    -   262V: first position detection magnet    -   262H: second position detection magnet    -   264V: first position detection sensor attachment portion    -   264H: second position detection sensor attachment portion    -   270V: first flexible printed circuit    -   270Va: fixed portion of first flexible printed circuit    -   270Vb: first linear portion of first flexible printed circuit    -   270Vc: bent portion of first flexible printed circuit    -   270Vd: second linear portion of first flexible printed circuit    -   270H: second flexible printed circuit    -   270Ha: fixed portion of second flexible printed circuit    -   270Hb: first linear portion of second flexible printed circuit    -   270Hc: bent portion of second flexible printed circuit    -   270Hd: second linear portion of second flexible printed circuit    -   272V: first flexible printed circuit attachment portion    -   272H: second flexible printed circuit attachment portion    -   G1: first lens group    -   G2: second lens group    -   G3: third lens group    -   G4: fourth lens group    -   G5: fifth lens group    -   G6: sixth lens group    -   G7: seventh lens group    -   Z: optical axis    -   Cv: axis passing through center of inner periphery of coil of        first voice coil motor    -   Ch: axis passing through center of inner periphery of coil of        second voice coil motor    -   L1: first straight line (straight line passing through magnetic        scale and optical axis Z)    -   L2: second straight line (straight line orthogonal to surfaces        of inner yoke portion and outer yoke portion that face each        other)    -   L3: third straight line (straight line passing through main        shaft and optical axis Z)    -   ZM: disposition range of magnet of voice coil motor    -   α1: disposition angle (angle formed between straight line S1 and        first straight line L1)    -   α2: disposition angle (angle formed between straight line S2 and        first straight line L1)    -   α3: disposition angle (angle formed between straight line S3 and        first straight line L1)    -   α4: disposition angle (angle formed between straight line S4 and        first straight line L1)    -   β1: disposition angle (angle formed between straight line S1 and        third straight line L3)    -   β2: disposition angle (angle formed between straight line S4 and        third straight line L3)    -   β3: disposition angle (angle formed between straight line S2 and        third straight line L3)    -   β4: disposition angle (angle formed between straight line S3 and        third straight line L3)    -   θ1: installation angle (angle formed between second straight        line L2 and first straight line L1)    -   θ2: installation angle (angle formed between second straight        line L2 and first straight line L1)

What is claimed is:
 1. A lens barrel comprising: a first shaft and asecond shaft that are disposed along an optical axis; a lens frame thatincludes a first sliding portion sliding along the first shaft and asecond sliding portion sliding along the second shaft and that issupported to be movable along the optical axis; a coil that is mountedto the lens frame and that surrounds an outer periphery of the lensframe; magnetic force applying members that are disposed at a pluralityof positions around the lens frame and that apply magnetic forces to thecoil; and a magnetic sensor that detects an amount of movement of thelens frame, wherein the magnetic force applying member includes a flatplate-shaped first yoke and a flat plate-shaped second yoke that aredisposed inside and outside the coil to face each other with the coilinterposed therebetween and a magnet that is provided at the first yokeand/or the second yoke, and in a plane orthogonal to the optical axis,the magnetic force applying members that are disposed on both sidesadjacent to the magnetic sensor are disposed in postures in which afirst angle formed between a first straight line and a second straightline is smaller than 45°, the first straight line being a straight linepassing through the magnetic sensor and the optical axis and the secondstraight line being a straight line orthogonal to surfaces of the firstyoke and the second yoke of the magnetic force applying member that faceeach other.
 2. The lens barrel according to claim 1, wherein the firstangle is equal to or smaller than 35°.
 3. The lens barrel according toclaim 1, wherein, in the plane orthogonal to the optical axis, themagnetic force applying members that are disposed on both sides adjacentto the magnetic sensor are symmetrically disposed with respect to thefirst straight line.
 4. The lens barrel according to claim 1, wherein,in the plane orthogonal to the optical axis, the magnetic sensor isdisposed at a position at which the first straight line and a thirdstraight line cross at a right angle, the third straight line being astraight line passing through the first shaft and the optical axis. 5.The lens barrel according to claim 4, wherein, in the plane orthogonalto the optical axis, the plurality of magnetic force applying membersare symmetrically disposed with respect to the third straight line. 6.The lens barrel according to claim 1, wherein, in the plane orthogonalto the optical axis, the magnetic force applying members that aredisposed on both sides adjacent to the magnetic sensor are disposed atpositions at which a second angle formed between the first straight lineand a fourth straight line is equal to or larger than 35° and smallerthan 55°, the fourth straight line being a straight line passing throughthe magnetic force applying member and the optical axis.
 7. The lensbarrel according to claim 6, wherein the first angle is smaller than thesecond angle.
 8. The lens barrel according to claim 1, wherein, in theplane orthogonal to the optical axis, the first shaft and the secondshaft are symmetrically disposed with respect to the first straightline.
 9. The lens barrel according to claim 1, wherein the magneticsensor is disposed within a disposition range of the magnet in adirection along the optical axis.
 10. The lens barrel according to claim1, wherein the first sliding portion includes a hole into which thefirst shaft is inserted, and the second sliding portion includes agroove to which the second shaft is fitted.
 11. The lens barrelaccording to claim 1, wherein the first sliding portion is disposedinside the coil, and the second sliding portion is disposed outside thecoil.
 12. The lens barrel according to claim 1, wherein the first yokeand/or the second yoke has a width and/or a thickness corresponding to amagnetic flux density generated by the magnetic force applying member.13. The lens barrel according to claim 1, wherein the lens frameincludes a magnetic scale provided at an outer peripheral portion of thelens frame, and the magnetic sensor is disposed to face the magneticscale and reads magnetic information of the magnetic scale to detect theamount of movement of the lens frame.
 14. A lens barrel comprising: afirst shaft and a second shaft that are disposed along an optical axis;a lens frame that includes a first sliding portion sliding along thefirst shaft and a second sliding portion sliding along the second shaftand that is supported to be movable along the optical axis; a coil thatis mounted to the lens frame and that surrounds an outer periphery ofthe lens frame; magnetic force applying members that are disposed at aplurality of positions around the lens frame and that apply magneticforces to the coil; and a magnetic sensor that detects an amount ofmovement of the lens frame, wherein the magnetic force applying memberincludes a flat plate-shaped magnet that is disposed to face the coil,and a normal line from a flat surface portion of the magnet from theoptical axis and a straight line passing through the optical axis andthe flat surface portion of the magnet form an angle.